Modern hearing assistance devices, such as hearing aids, are electronic instruments worn in or around the ear that compensate for hearing losses of hearing-impaired people by specially amplifying sound. Hearing-impaired people encounter great difficulty with speech communication in multi-talker settings, particularly when attention needs to be divided between multiple talkers.
Current hearing assistance technology employs single-microphone noise reduction algorithms in order to increase perceived sound quality. This may also reduce listening effort in complex environments. However, current noise reduction algorithms do not increase speech intelligibility in multiple-talker settings. In contrast, use of static directionality systems such as microphone arrays or directional microphones in hearing aids can increase speech intelligibility by passing signals from the direction of a target talker, typically assumed to be located in front, and attenuating signals from other directions. Recently, adaptive directional systems have also been employed that adaptively follow a target with changing direction.
Directional systems only increase speech intelligibility when the direction of a target talker, or the talker of interest to the listener, relative to the listener's head remains constant in front of the listener or can be identified unambiguously. However, in many real-world situations, this is not the case. In a dinner conversation, for example, where speech from multiple concurrent talkers can reach the ear from different directions at similar sound levels, identifying the desired target location is a difficult problem. Active user feedback via a remote control may help in static scenarios where the spatial configuration does not change. However, user feedback would not be practical in situations where targets can change dynamically, such as two or more alternating talkers in a conversation.
Accordingly, there is a need in the art for improved systems and methods for enhancing speech intelligibility and reducing listening effort in multi-talker settings.